Keep the magic secret is the tagline for Series 1 of the show Merlin.
It is used for publicity and is designed to reflect a key aspect of the show's protagonist, Merlin.
"It's lonely to be more powerful than any man you know and have to live like a shadow. To be special and have to pretend you're a fool. I know how it feels, I understand."
—Merlin to Gilli
"I just want Arthur to trust me and to see me for who I really am."
—Merlin to Gaius
"If it comes to a choice between me saving peoples lives and revealing who I really am, there is no choice."
"You can't let Arthur know about your gift.
—Merlin and Hunith
"How many times, Merlin?! How many times must I drive it into that thick skull of yours that your magic is a secret to be guarded with your life?! What were you thinking??!!"
—Gaius to Merlin
"Father, please! I can't allow this! This is madness! There's no way Merlin is a sorcerer. ... Merlin is a wonder, but the wonder is that he's such an idiot. There's no way he's a sorcerer."
"Arthur thinks he is so sharp! But even when I told him I was a wizard, he still couldn't see it."
"Sometimes they're pretty hard to spot."
"Well, maybe I should go around wearing a pointy hat."
—Merlin and Gaius

The tagline is based on the fact that Merlin has magic but in Camelot such powers are forbidden, which is made painfully clear in The Dragon's Call (Series 1, Episode 1) when a suspected sorcerer is executed as Merlin first arrives in Camelot. On pain of death, Merlin must keep his gifts a secret. The only people in the show who know about his powers are Hunith, Merlin's mother, William, Merlin's childhood friend, Gaius, Kilgharrah, Nimueh, Mordred and the Druids, Edwin Muirden, a warlock who was killed after attempting to get revenge on Uther for the deaths of his parents, Lancelot, a deceased knight of the round table, Freya, Merlin's deceased love-interest who was cursed to be a Bastet and returns as the Lady of the Lake, Taliesin, an ancient warlock and seer, Gilli, a young and misguided warlock who left Camelot after Merlin opened his eyes to how magic should be used, stating that their paths may cross again, The Cailleach, Julius Borden, a student of Gaius who is thought to have died while pursuing a dragon's egg, Agravaine, Arthur's uncle who is also deceased, Alator of the Catha, a warrior and High Priest of the Old Religion, who swore his allegiance to Merlin, and many of the minor foes Merlin has defeated. Of these, Gaius, Kilgharrah, Lancelot, Freya, and Nimueh have played a major role in the plot of the show as a whole. Mordred will be returning in Series 5 and will serve as a main character. Gaius, Kilgharrah, and Lancelot were the only main characters to know Merlin's secret and to be his long-time allies. Gaius is Merlin's mentor and main confidant. At one point, during The Witchfinder (Series 2), Gaius submits himself to being sentenced as a sorcerer in order to protect Merlin's secret when Aredian planted evidence implicating Merlin as a sorcerer. Merlin then proved Gaius's innocence. In The Mark of Nimueh (Series 1), Merlin confessed to sorcery.

Protagonists Who Know Merlin's Secret Edit

Person Status Photo
Gaius Alive Gaius1
Freya † - returned as Lady of the Lake Freya1
Lancelot † - returned as Shade before dying again Lancelot1
Kilgharrah Alive Kilgharrah 100
Arthur Pendragon † -Killed by Mordred
Guinevere Pendragon Alive

Antagonists Who Knew or Discovered Merlin's Secret Edit

Person/Creature Status Series Photo
Mary Collins

Series 1

Series 1

Series 1

Series 1
Sidhe Elder possibly †

Series 1
Edwin Muirden

Series 1
Edwin profile
Questing Beast

Series 1
Questing beast in Merlin
Tauren and some of his men

Series 1
Tauren vs Merlin
Kilgharrah Alive Series 2
Kilgharrah 100
(possibly) Aredian

Series 2
Troll (Catrina)

Series 2


Series 2

† - returned as Lady of the Lake

Series 2
Mordred † -Killed by Arthur Pendragon Series 2/Series 5
Mordred.. notice his shoulder
Cornelius Sigan

† - soul preserved

Series 2
(possibly) Manticore

Series 3

Series 3
The Changeling

† - host alive

Series 3
The Changeling
Goblin Alive - locked away Series 3
Goblin's Gold

Series 4

Julius Borden

Series 4
Agravaine de Bois

Series 4
Uther Pendragon

† - ghost

Series 5
Death song uther pendragon
Morgana Pendragon † killed by Merlin Series 5
Morgana in episode 12

Other Characters Who Knew Merlin's Secret Edit

Person/Creature Status Photo
Hunith Alive
The Cailleach Alive
Gilli Alive
Melling Gilli
The Vilia Alive
Alice Alive
Anhora Alive
Anhora infoboximage
Iseldir Alive
Iseldir m
Grettir Alive
Grettir promopic
Fisher King
Taliesin Unknown
Taliesin (16)
Alator of the Catha † -Killed by Morgana Pendragon
Aithusa Alive
Aithusa Arthur's Bane Part Two
Druids Alive
Mordred † -Killed by Arthur Pendragon
Community content is available under CC-BY-SA unless otherwise noted.